What's New and Noteworthy

What Is Joint Effusion?

Small amount of fluid in a joint is normal. It is a lubricant for joint motion.

When fluid increases abnormally it is described as an “effusion”. This is excessive accumulation of fluid in the joint.

Joint effusion can be due to a number of different things. It can be caused by bruising of the joint from trauma or from overuse of the joint. It can come from an inflammatory condition such as arthritis or even infection.

Draining the excess fluid from a large joint such as the knee can help relieve pain and laboratory testing of the fluid can help determine the cause of the effusion.

Laboratory tests can be performed to clarify the diagnosis.